Electrical heating system



Nav. '2, 1937. J. M. wEYDE-LL 2,097,483

ELECTRICAL HEATING SYSTEM IRT/672250? 7 Jy eZZ Patented Nov. 2, 1937 I 1 l UNITED STATES PATENT OFFICEv ELECTRICAL HEATING SYSTEM Jari M. Weydell, Chicago, Ill.

Application May 17, 1935, Serial No. 21,965

7 Claims. (Cl. 219-20) This invention relates to an electrical heating and they are recessed at the side, as shown at 3. system particularly adapted for use on auto- Projecting into this recess is a field winding 4 mobiles, and has for its object to provide a. new which is attached to the automobile in any deand improved system of this description. sired manner so as not to rotate, as for example The invention has as afurther object to provide by the supporting member 5. 'Ihe field winding 5 vide an electrical heating system for automobiles 4 may consist of one or more individual coils to be used to supply current to an electric heatconnected to the battery and to the electric ing device on the automobile, as well as to sup.- heater. Since the eld winding 4 is stationary ply current to the battery. and does not rotate, all necessary connections 10 The invention has asafurther object to provide may be made directly to the terminals, no 10 such a system wherein there is a magnetic inbrushes or collecting rings being required. This duction clutch in conjunction with the gengreatly reduces the esxpense and increases the erator and interposed between the generator and reliability of the device. the engine, by means of which the electrical out- The supporting member 5 has a laterally proput of the generator remains substantially conjecting part 1 to which the generator frame 8 is 15 stant over a wide range of speeds of the engine, connected. The connection of the generator regardless of the cutting in or out of any or all frame is made by a separate ring 9, which is of the coils of the heating device. preferably non-magnetic and which is fastened The invention has other objects which are to the support 5 by the fastening devices IU. more particularly pointed out in the accom- This ring has a laterally projecting part Il which 20 panying description. is fastened to the generator frame by the fas- Referring now to the drawings, Fig. 1 is a view tening devices l2. This ring 9 has a web i3 of the front end of the automobile showing one Which DIOJ'BCSS inwardly and WhiCh SllIrOlmdS form of electrical heating system embodying the the armature shaft I4, being perforated to reinvention; ceive it, and which forms a. support for the bear- 25 Fig. 2 is a diagrammatic view showing a modiing I4a of the armature shaft. fied construction; The frame 8 of the generator has poles I5 Fig. 3 is a diagrammatic view showing a furcarrying coils I6. The poles are opposed to the ther modified construction; armature I1. This armature has coils I8 eX- Fig. 4 is an enlarged longitudinal sectional tending all around it and these may be the 30 view taken through the generator shown in standard armature coils., AThe generator has a Fig, 1; plurality of poles l5 and a plurality of shunt Fig` 5 is a'sectional view taken on line 5 5 coils I6. There of course can be any even num- Of Fig, 4; and ber of poles and any number of coils desired. Fig. 6 is a sectional view taken on line 6-6 The armature has a large .number of coils I8, 35 of Fig. 4, the number depending upon the conditions. For

Like numerals refer to like parte throughout example, I have used with good result twentythe several gures. ve of these coils.` The other end of the arma- In the drawings I have illustrated the device ture Shaft iS Supported by a bearing I9 in a Cup 40 in Connection with an automobile, as it is parshaped bracket 20 which is attached to the frame 4o ticularly adapted for use in connection there- 8 0f the generator by fastening devices 2l. This with, 1n the preferred form of the invention I armature has a commutator 22 with the brushes provide a magnetic clutch and a generator whose 23 and 23a on said commutator. shafts have' a common axis, The magnetic The magnetic clutch comprises the clutch pole clutch consists of a clutch' pole or member pieces la which are fixed to the shaft and rotat- 45 which is attached to a shaft 2 driven by the ened by the angina Opposed t0 the Clutch 100165 iS gner This shaft may be the engine Shaft, it the other member .24 of the'clutch, which is the may be the generator shaft, or it may lbe some rotor and Wmch 1s a' lammated iron ring 24 other shaft, but whatever the shaft is, it is driven extendmg e-ntlrely .around th? clutch. pole pleces' by the engine. Elrligictv lblazt; rs1? rggs 1s apnenes lof highly 50 s co er, a uminum, 2 isclfllovlilsftlg ltlhzeshtvl tg; afelazf; or other suitable material. These bars should l fit closely to the inner face of the ring. 'I'hey from the engine Shaft 2b. ThlS Clutch D018 1S may even have a part of their periphery exposed of itself provided with separated pole pieces la. if desired. There is an air gap 26 between the 55 inner face of the iron ring and the outer faces of the clutch pole pieces. 'I'his gap should be very small in order to obtain a high magnetic ux density in the magnetic circuit which includes the iron ring. Itis preferably 15/1000th of an inch or less.

Attached to this iron ring 24 is a spider or web 21 of highly conductive material, such as copper, brass, aluminum, or the like', which is perforated to receive the shaft I4 and is rigidly fastened thereto, the bearing Ilia or" the armature being between its hubV and that of the web I3. The armature shaft has another "bearing Ib between it and the clutch pole or member l. This is not actually necessary, but is a construction which makes the device compact. On the other side of the iron ring 24 is a ring 28, which is also of highly conductive material, such as copper, brass, aluminum or the like, and the bars 25 connect with the ring 28 and the spider 21.

To secure compactness, the magnetic clutch and generator are mounted on the engine 21a in some suitable manner. As herein shown, the engine has a forwardly projecting part 21h and the member 'l has a supporting member 1a, attached thereto. The supporting member 'la passes through an opening in the member 21h and is held in place by the nut 1b. There is an annulus or iiangeflc attached to the member 'I which rests on top of the member 21h. The shaft 2 has a bearing 2c which is carried by a support 2d attached to the supporting member 3.

The magnetic iiux produced by current owing in the field windings 4 passes through the pole pieces la, cuttingthrough the iron ring 23 and returning through the frame 1 to the pole l. When the shaft 2 is rotated, the magnetic fiux, which is concentrated at the pole pieces la., is caused toy move across the conductive bars 25 of the iron'ring 24, thereby inducing potentials in the said bars.. Since the bars are short circuited by the conductive end plates 21 and 28, large induced currents ilow in these closed circuits, which in turn set up magnetic forces tending to oppose the motion causing the induction, and thereby exerting a pull or torque on the iron ring 24. This torqueis transmitted through the spider 21 to the armature shaft I4, thus causing the armature I1 tobe rotated. The rotation of the armature between its pole pieces generates current which is collected at the commutator in the usual manner.

The magnetic clutch, when employing a single field coil, providesy a substantially constant pull or torque on the armature shaft. The generator on the other hand, being generally shunt wound, tends to increase its output potential when its speed of rotation is increased. Therefore, more power is required' to drive the generator at higher speeds,l but the magnetic clutch will not deliver this Vadditional power to the armature shaft because ofA its limited torque. Thus, as the speed or rotation of' the clutch driving member I increases, the amount of slip increases, tending to keep thearmature rotating at the desired speed,

vregardless of vwide variations in the driving or motor speed.

l Byproperlyfdesigning the magnetic circuit of the clutch Eandthe electrical circuits comprising the, conductivebars and end plates of the iron ringy 24, and taking into consideration the characteristics of the generator which is to be employed, I can lobtain by this device a good averr`age regulation of the system under all ordinary operating conditions.

ample charging current at all times.

generator output, the brush 23 of the generator being grounded at 23h. The coil I6 of the generator is grounded at lSa and a series or compensating coil 4b is connected so that it carries only the current which flows to the heater coils 30 and 3|, which are grounded at 32 and 33 and which are controlled by the switches 34 and 35.

It is of course evident that any number of coils may be used in the heater, and I have shown diagrammatically these two heating elements which can be placed at different positions in the automobile, one for example, the heater 30 being placed at the front of the automobile for the people in the front seat, and the other one being placed in the rear for the people in the rear seat. These heating coils would preferably be placed in reflectors 30a, arranged to direct the heat in the direction desired, the reflectors preferably adjustably mounted, as by means of a pivot 30h.

In this case the shuntcoil 4c is designed so that its magnetic iiux provides suiiicient drive through the clutch to supply the battery 4a which is grounded at 22a and connected to the generator output by conductors 22h and 22e with The coil 4b is connected in this circuit by the conductor 22d. The series or compensating coil is electricallyinsulated from the shunt coil, but the two are contiguous and comprise the eld Winding, generally designated as 4.

The direction of the series coil is such that the load current flowing through it generates additional magnetic ilux in the same direction as that produced by the shunt coil thus increasing the torque applied to the armature shaft I4 and supplying additional driving power to the generator as it is needed to supply current .to the heater, etc. With this arrangement, the power output oi` the generator varies in proportion to the electrical demand of the system, the voltage remaining substantially constant regardless of the speed of rotation of the clutch driving member l.

In some applications of my magnetic clutch I have found it desirable to employ a third method of regulation, particularly where the output potential of the generator must be kept constant within very narrow limits. In this case, shown in Fig. 3, Iemploy a single field winding 4 in the clutch, designed as described for average performance, but in addition I make use of an external voltage regulator 36. This regulator may be of the conventional type, consisting of a voltage sensitive relay with a spring adjustment 31 for setting the control point as required. The relay contacts 38 are shunted by a resistance 39 and connected in series with the circuit 4I! which supplies the clutch iield winding 4 with current. When the generator output voltage is below the control point, the spring 31 holds the relay con- The coilli isgroundedatllandthecircuit leadingtotheheatingcoilslandilisconnected directly with the conductor leading to the generator. Thus with this relatively simple means the voltage of the system may be accurately maintained at a constant level regardless of wide nuctuations in driving speed or load current, or both.

I have found that the system comprising a magnetic clutch driving a generator is extremely complex and dimcult to determine quantitatively inall oi its aspects, due to the many variables which operate simultaneously. However, by taking into careful consideration the speed, slip and load char acteristics oi' both the generator and the magnetic clutch, I can so design and PI'OPOrtion the active parts`of the clutch and its associated circuits that I obtain an overall performance oi' the system, even with single coil field winding, which is superior to direct drive generator arrangements employing the socalled third brush method 'oi regulation now in general use. My invention also provides the added advantage of always operating the generator at a relatively low speed, regardless of the number oi coils of the heater that may be in circuit, thus reducing wear on bearings, brushes and commutatorand increasing the life and reliability of the generator. This device responds to either the electrical load or the batterycondition or to both.

I claim:

1. An 'electrical heating system for automobiles comprising an electrical generator, a driving device therefor out of mechanical connection with the generator, throughout the entirev operation oi' the device, a variable speed motor for driving the automobile, said generator and driving device ilxed in position on the automobile in proximity to said motor, a driving connection from said motor to said driving device, an electric heater mounted on said automobile, an electrical connecting device for connecting said electrical heater in circuit with said generator, and means for causing the speed oi' the generator to fall behind the speed of the driving device as the speed oi the driving device increases, whereby a substantially constant potential is maintained' for the current passing to said heater.

2. An electrical heating system for automobiles comprising an electrical generator, a variable speed motor for driving said automobile and said generator, said motor and generator mounted on said automobile in proximity to each other, a heating device mounted on said automobile and electrically connected with the generator, and a connecting device between the generator and the motor for maintaining the electrical clnrent generated by the generator at a substantially constant voltage regardlessof the speed of thel motor, whereby the heating device is supplied with a substantially constant voltage current throughout the variations in speed of the'motor.

3. An electrical heating system for automobiles comprising an electrical generator, a variable speedmotoriordrivingsaidautomobileand said generator, said motosl and generator mounted on said automobile in proximity to each other, an electrical heater connected in circuit with said generator, and a variable driving connection between the generator and the motor which automatically decreases the speed o! the generator relative to the speed of the motor as the motor is speeded up, so as to deliver a substantially constant potential current to the heater.

4. An electrical heating system for automobiles comprising an electrical generator, a variable speed motor for driving said generator, said motor and 'generator mounted on said automobile in proximity to each other, a heater operatively connected in circuit with said motor, a magnetic connecting device for transmitting the driving power from the motor to the generator, and means associated with said magnetic connecting device for providing a slip between the magnetic connecting device and the generator, which slip increases as thespeed oi' the motor increases, whereby a substantially constant potential current is delivered to said heating device.

5. An electrical heating system i'or automobiles comprising an electrical generator, variable speed motor, said motor and generator mounted on said automobile, the generator mounted upon said motor, a heating device connected with said electrical generator, a driving connection between the generator and the motor, and means forming a part oi said driving connection for varying the speed of the generator inversely as the' speed of the motor varies, whereby a substantially constant potential current is delivered to the heating device.

6. An electrical heating system for automobiles comprising an electrical generator, a driving device thereforA out of mechanical connection with the generator a variable speed motor for driving said automobile and said driving device, said driving device mounted on said motor, said generator mounted on said driving device, an electrical heater mounted on said automobile, a connecting device i'or connecting said electrical heater in circuit with said generator, and means for causing the speed of the generator to fall behind the speed of the driving device as the speed of the driving device increases, and a separate regulating device, a circuit connecting said regulating' device with said driving device, whereby a substantially constant potential ismaintained for the current passing to said heater.

7. An electrical heating system for automobiles having hoods, comprising an internal combustion engine for driving the automobile, a generator, a magnetic driving device therefor, said generator and magnetic driving device mounted on said engine beneath the hood, a driving connection between the magnetic driving device and the engine, a heater on the automobile, and electrical connections between said generator and ,said heater.

JARL M. WEYDELL. 

